This invention relates to an apparatus used to withdraw liquified gas from a storage vessel or tank and to deliver the liquified gas to a smaller vessel from which it is dispersed in a spray, as for example, a cryosurgical instrument.
It has long been known to use liquified gas (such as helium, nitrogen, oxygen, air, freon, xenon, carbon dioxide, etc.) to freeze healthy or diseased tissue, and thereby necrotize the tissue. For instance, one well-known use of liquified gas is in the field of cryosurgery for the removal of lesions, both on the skin or internally. Usually, the object is to remove the lesion by destroying the tissue while maintaining adjacent portions of the tissue structure in place.
In such instruments the liquified gas is delivered through an insulated tube from a storage vessel or bottle to an applicator, where it is dispersed in a spray. Examples of such instruments are shown in U.S. Pat. Nos. 3,823,718; 3,534,739; and 3,702,114.
The apparatus of the present invention is used to charge the storage vessels or bottles of such instruments with a liquified gas refrigerant by withdrawing the refrigerant from a large tank supplied by a distributor or gas manufacturer and transferring it to the smaller storage vessel or bottle.